Piston-ring.



F. EQDAVIDSON.

PISTON RING.

APPLICATION FILED DEC. H, 1914.

1 1 72,677 v Patented Feb. 22, 1916.

2 SHEETSSHEET I.

F. E. DAVIDSON. PISTON RING.

APPLICATION FILED DEC. H. 19M.

1,1 72,677. Patented Feb. 22, 1916'.

2 SHEETSSHEET Z- FRANK E. DAVIDSON, 0E NEW YORK, N. Y.

' Specification 01 Letters Patent.

PISTON-RING.

Patented Feb. 22, 191

Application filed December 11, 1914. Serial No. 976,540.

To all whom it may concern:

Be it known that I; FRANK E. DAVIDSON, a citizen of the United States, and a resident of New .York, borough of Manhattan, city and State of New York, have invented certain new and useful Improvements in Piston-Rings, of which the following is'a' description in such full, clear, and exact terms as will enable any person Skilled in the art to which it pertains to make and use the same. h

My invention relates to an improvement in piston rings intended particularly for gas .and other internal combustion engines, but

useful on all pistons as will be apparent" from the following description.

The special object of the invention is to h construct the ring so that it will resist high pressures and prevent the explosion in the engine froni driving the gases past the piston on the working stroke thereof. -I-attain this end by a peculiar construction which is illustrated in the accompanying drawingand will now he specifically de-- scribed. 7

In the drawings Figure 1 is a perspective .view showing the two parts of the ring- (which ordinarily lie close together) separated better to illustratetheir construction. and operation. Figs. 2 and 3 are perspective views of a modification and Fig. 4 is a cross section on line H of Fig. 3.

Referring to Fig. 1, the two parts a of the ring are each composed of two metal strips a and a These strips a and a are resilient and are of circular form, one lying outside of the other in true concentric arrangement. The strips-do not form complete circles,'but

are slightly separated at their ends by gaps II. The ends of one strip. however, overlap gthe ends of the other and'are fastened together by rivet c in the inner ring which fits in a hole in theouter ring, so that the two strips 0; and a form the unitary part a."

These parts a are placed vertically one above the other and each'part isfurnished with a pin (1 the same being located (on its respec. tive part) opposite the rivet 0 so that-the pin d of the one part a enters one of thegaps b of the other part... This allows a'fvery slight rotating niotion of the parts a iela tively to each.other but prevents any man terial turning such as would allow the parts a a one-half rotation and bring the gap 1) of one part into registry with the gap 1) 5,5

of theother. It. should be noted that the 7 result of this arrangement is that the strips a?" nude composing each part may freely. expand and contract to keep the ring tight against the cylinder walls. At the same time it is impossible for the parts a to turn so that the gaps b may register. This insures that there be at no time any passage vertically past which the gases can leak, the ring. always presenting at all points an unbroken circumferential surfac m The modificationused in Figs, 2 to 4.33. 1 commodates one pair of ringsinsteadpi .two.- The concentric split rings a and a,

are held together at c and are attached to ex- 7.0

pend and contract as described in reference to the other form of the invention. When the ring is innse the stepped lapped joints are in contact as" indicated by. thejbrokein lines in Figs. '2 and 3 so that there is no 15 way in which the gas may escape past the rlng. Having thus-described my invention what i I claim as new and desire to secure by Letters. Patent of the United States is 1. A piston ring composed of'two expansive and contractive, concentrically arranged spring, ringparts, each being split,- one end of one split part overlapping theopposite end of the, other split part and afastening connecting said'overlapping ends,

'oneen'd of each part. being free and the resihentaction of the two ring parts being said parts 7 edgewise one upon the. other against materlal r elative rotation.

3. A piston-ring composed of two parts lying edgewise one upon. the other, eachpart termed of two concentrically arranged 'resflientlspm rings w fiier pp g ends 1 fastened together, and means for holding signed my name in the presence of two wit said parts one upon the other against mamesses. terial relative rotation, said means consisting of pins on the parts adapted to fit in 5 gaps between ends of the rings of the other Witnesses:

parts. PATRICK A. 130mm,

In testimony whereof I have hereunto EIIDA Tmmnx.

FRANK E. DAVIDSON. 

